Early Results from the 2023 Eclipse Medium Wave Recordings

During the annular eclipse of 2023, HamSCI organized 13 volunteers in Canada, US, Mexico and Portugal to record the entire medium wave band (525-1705kHz) using software defined radios, both during the eclipse and for the same time period on other days, as well as during dawn and dusk periods. This medium wave data should extend our understanding of the eclipse's influence on the ionosphere by using frequencies well below HF. Since the eclipse, all 10 TB of medium wave data has been gathered and archived, followed by preliminary processing using inexpensive commercial software, such that all signal strength data from each participant is now available to 0.1Hz resolution for all broadcast channels.  In addition, for all broadcast channels, and from every participant, useful visualization of signal variations during the eclipse is now available, as well as for all other time periods recorded. Many participants did see an effect of the eclipse on received signals.  Comparisons of their rates of success compared with percentage of totality at their locations will be discussed. It's already possible to support some of the science aims of HamSCI with this gathered and archived data.  Examples will be given of whether signal strength changes observed were symmetric compared with the onset and recovery timing of the eclipse. These changes will likely have been due to ionospheric response as the eclipse progressed. Visual examples will also be given of comparisons between the eclipse's effects on target signal characteristics to the effects caused by the passage of the daily dawn and dusk terminator.